S'ok, I have the code, in fact it has been requested so many times that I have memorised it, and learned a few words of Danish to get it back to normal.
It happens at random intervals, and seems to have started after I had a new battery fitted (by the AA). Can't find any options on the menu system (1.8 Zetec Navtec) other than switching off the code. Any ideas? The battery connections seem tight.